The Mekhilta DeRabbi Yishmael examines the phrase "according to the mohar of the virgins" and applies a distinctive rabbinic technique to determine the monetary amount it refers to. The result is a teaching that, in the Mekhilta's own words, "comes to teach but emerges as learning."
The word mohar refers to a bride-price, the payment a man makes to a woman's father upon marriage. The Torah uses this phrase in the context of a man who has violated an unmarried woman and must now pay her father. But the verse in Exodus does not specify the exact amount. It says only "according to the mohar of the virgins," leaving the sum undefined.
To fill this gap, the rabbis turned to a parallel verse in (Deuteronomy 22:29), which addresses the same situation and specifies the amount: fifty silver shekels. The Mekhilta then applies a principle of mutual illumination between the two texts. The Exodus verse, which seemed to be teaching something new about the mohar, actually "emerges as learning" from Deuteronomy. It does not add new information. Instead, it confirms and receives its definition from the parallel law: just as there, in Deuteronomy, the amount is fifty silver, so here, in Exodus, the amount is fifty silver.
This interpretive move, where one verse turns out to be explained by another rather than introducing independent content, is a recurring feature of rabbinic exegesis. The rabbis called it a passage that "comes to teach but ends up learning." It reflects the rabbinic conviction that the Torah is a unified system in which every verse illuminates every other verse. No passage stands alone. The mohar of the virgins in Exodus has no fixed amount on its own. It receives its meaning from Deuteronomy, and in doing so, demonstrates that the Torah speaks with a single, harmonious voice across its different books.